Malicious PDF — malware analysis report

Static analysis result for SHA-256 40ac733e76870574…

MALICIOUS

PDF

96.3 KB Created: 2021-08-07 18:49:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ad081e6f417ae7e34027b15851eaadef SHA-1: b4d6f39ee74b915250004f482a3f89a8700d298d SHA-256: 40ac733e768705742f75d8da6403fc020ad41c8468b59e23e671460c478642b9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous URLs, many hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The primary function appears to be redirecting users through a series of links, some of which are hosted on disposable domains or compromised upload directories.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/6b2a95ad224b7edbe46f282357981bcb/lezavewogavige.pdf In PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/ckr9tjunlc3bus2ua05nr8mpd0/43243552131.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d98fb4f2c---19723308514.pdfIn PDF document text
    • https://smartmedia.ro/app/webroot/files/userfiles/files/67669102629.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606efad196da4---5192469460.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/63023412177.pdfIn PDF document text
    • http://xboxheerlen.nl/userfiles/file/90750680514.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/47050042742.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/606339de4c634d8f8cb2ceb91f5e9d3e/62061922324.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/sgbtu3q4tk5ojnlicb2m5j6rbd/45979251846.pdfIn PDF document text
    • https://alrashed-alsaleh.com/userfiles/files/kejulufalufimunanosakuzus.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/nulijefonobaj.pdfIn PDF document text
    • http://talk200.com/admin/admin/uploadfiles/file/95512179967.pdfIn PDF document text
    • http://skyline1968.com/clients/74864/File/31411352702.pdfIn PDF document text
    • http://kcde.kr/userfiles/file/nigakirafenelofepiwabota.pdfIn PDF document text
    • http://essiac.cz/UserFiles/file/dowiget.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/bc4f8c769a3da0bc968761def2b99807/95277471527.pdfIn PDF document text
    • http://co-wemart.com/careeruserfiles/file/89100056064.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/48576808503.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/b8b70d2dc7270a3bd734890e38883711/47719325520.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a68eb2d3108---jupoxowumebirokifova.pdfIn PDF document text
    • http://renovator.cz/files/file/suxug.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/xidosadikidipew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=gina+wilson+all+things+algebra+answer+key+2017PDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011123.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11123 11204 bytes
SHA-256: 5c8b1392c687176f4aeb7b0bf9bef1cf92e6cdbf6758e1e071f82e44241cadac
font_01_sfnt_off00012b8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B8C 18164 bytes
SHA-256: 77dbcd2c5fd30e952989686488467fcd6e4c5310a493218eba362e6b88201880
font_02_sfnt_off00015b3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1